Gas burner assembly

ABSTRACT

Fuel burner assembly for the combustion of gaseous fuels with a heating value over 3,000 Kcal./Nm.3 in which one and the same member is provided for controlling output, keeping the flame length constant and controlling the air-gas proportion. The said member is an axially displaceable mixing member actuated by a solenoid with a soft iron yoke mounted on the mixing member. The needle of the valve for the gas is also mounted on the mixing member having means for engaging it in an axial direction. The casing of the burner is divided into at least two chambers, by a dividing ring, said chambers being connected by passages. Both the mixing member and the dividing ring have a closing surface serving to close the aperture arranged in said dividing ring.

United States Patent [72] Inventor Attila Biro Miskulc, Hungary 2| App].No. 811,996 [22] Filed Apr. 1, 1969 [45] Patented June 29, 1971 [73]Assignee Koho-es Gepipnri Miniszterium Tuzelestechniltai KutatointezetMiskolc-Egyetemvaros, Hungary [32] Priority Apr. 8, 1968 [33] Hungary[31] 81-300 [54] GAS BURNER ASSEMBLY 7 Claims, 1 Drawing Fig.

[52] US. Cl 239/415, 239/S85,137/607 [51] Int. Cl F23d 13/38 [50] FieldofSearch 239/4173, 406, 585, 414, 415, 413; 137/607 [56] ReferencesCited UNITED STATES PATENTS 2,022,513 11/1935 Macchi 239/4173 PrimaryExaminerLloyd L. King Attorney-Young & Thompson S'll'ltAC'll: Fuelburner assembly for the combustion of gaseous fuels with a heating valueover 3,000 KcaL/Nm. in which one and the same member is provided forcontrolling output, keeping the flame length constant and controllingthe air-gas proportion. The said member is an axially displaceablemixing member actuated by a solenoid with a soft iron yoke mounted onthe mixing member. The needle of the valve for the gas is also mountedon the mixing member having means for engaging it in an axial direction.The casing of the burner is divided into at least two chambers, by adividing ring, said chambers being connected by passages. Both themixing member and the dividing ring have a closing surface serving toclose the aperture arranged in said dividing ring.

PATENTED JUN29l9?l 3,589,619

INVENTOR /4T T/LA 49026 By %7 ra /4 6w) ATTORNEYS GAS BURNER ASSEMBLYThe invention relates to a fuel burner assembly, particularly forburning gaseous fuels having a caloric value exceeding 3,000 KcaL/Nmf,in which the internal constructional design of the burner device permitsto control and adjust the output and the air-gas proportion, with apractically identical flame length for the various outputs, as well as aperfect combustion of the fuel for all outputs. Accordingly, theinvention permits to realize the .required heating operation in the mostadvantageous manner, with a minimum of fuel input.

The automatic control ofthe air-gas proportion in conformity withrequirements has not been satisfactorily solved in the known gas burnerassemblies. In some cases valves or valve sets outside the burner unithave been provided, whereby the burner device has been rendered moreexpensive, voluminous and difficult to build in.

In the known burners the flow of gas and air is identical for small andlarge outputs. As a result, the flame is longer for large outputs andshorter for small outputs. This entails, especially in the case of highoutputs, a longer flame than desirable, and a too small flame for lowoutputs. As a result, incomplete combustion of the gases, or combustionoutside the furnace chamber are encountered, particularly in conjunctionwith high outputs in furnace chambers with temperatures below 800 C.,whereas in the case of low heat or simmer flame deleterious localoverheating occurs.

In conventional burners special means are provided for controllingoutput, air-gas proportion and flame length, which render the burnerdevices complicated and expensive.

It is the object of the invention to produce a burner assembly in whichone and the same member is provided for controlling output, keeping theflame length constant and controlling the air-gas proportion, wherebythe air-side resistance of the burner is diminished, flue gases areadvantageously dis tributed over the furnace chamber, and highefficiency of combustion by means of simple and economical construction.

These aims are realized according to the invention by lead ing thecombustion air over different paths across the control members, with theaid of a uniaxially disposed control arrangement actuated by a singlesolenoid, thus producing slower mixing for low outputs and quickermixing for higher outputs. The same actuation directly controls orregulates, without the need for any additional member, the gas input,i.e. the output of the burner, ensures the constancy of the mostdesirable gas-air proportion and dispenses with expensive externalcontrol means, which may be difficult to coordinate.

Such operation of the burner has the following main advantages over theknown solutions:

1. The adjustable flame length, practically independent from loading,ensures the most advantageous heat transfer in firing chambers, forexample in the firing chambers of industrial furnaces.

2. The mixing disc actuated by the solenoid not only con trols flamelength but also serves to adjust the output and the gas-air proportion,whereby all these controlling measures are considerably simplified, thusreducing the cost of the equipment.

. Even for satisfying the most complicated control requirements only onemagnetic safety valve outside the burner, is provided, so as to permitconsiderable reduction of the size and weight of the equipment.

The invention relates to a gas burner assembly, particularly for thecombustion of gaseous fuels of a caloric value over 3,000 Kcal./Nm.,which has a fan preferably driven by an electric motor, a fuel inlet, agas valve, a gas nozzle, igniting and monitoring members, said burnerassembly consisting of the following components, arranged uniaxially ina common casing which is conveniently composed of several parts; adriving motor, a fan, a solenoid, enclosing a compression spring, anaxially displaceable mixing cone, a gas needle valve joining the cone, acompression spring disposed on said needle, and a stationary gas nozzle;the soft iron yoke of the solenoid is mounted on the mixing cone, bothcompression springs engage the mixing cone, directly or indirectly, andthe internal space of the casing is divided into at least two chambers-asolenoid chamber and air chamber-said chambers being connected bypassages.

The invention will be further described by way of example with referenceto the accompanying drawing, representing one embodiment in longitudinalsection.

Fan 9 driven by an electric motor 1 disposed in the motor chamber 3conveys the combustion air from a fan chamber 5 through passages 6, 7, 8and 10 into a solenoid chamber 32 where a solenoid 11 is mounted on apartition 4. On said partition 4 a rod 30 is mounted axially, on which acontrolling or mixing cone 12 is so arranged as to permit sliding of thecone on the effect of the opposed forces of compression spring 14 and asolenoid 111. When the solenoid 11 is switched on, the soft iron yoke 13mounted on the mixing cone is displaced towards the solenoid andcompresses spring 14. Thereupon a passage is opened along thecircumference of the mixing cone 12 between said cone and a dividingring 26 for the air to stream from the solenoid chamber 32 into an airchamber 33. When the solenoid 11 is switched off, the spring M pushescone l2 forward, whereby opening 28 on the circumference of the disc 12is closed, so that air can stream into the air chamber 33 only throughthe small-diameter passages 22.

In the switched-on condition of the solenoid 11 the compressed spring 27draws the valve needle 24 backwards, so that the gas amount required forhigh heating output may freely stream through a gas nozzle 20. In theswitched-off condition of the solenoid 111 the stronger spring 141compresses spring 27, the valve needle 24 advances and reduces the gasin feed. A threaded control member 29, disposed on the front part ofcone 12 serves for controlling the gas-air proportion by checking theadvance of valve needle 24 dispensing the gas. A collar 31 arranged oncone 12 has a helically worked surface causing the combustion air tostream with turbulence, when high heating output is desired, wherebyflame length is diminished. A baffle 18 of truncated conical shape isdisposed on the front part of the burner for securing completecombustion for low heat or simmer" heat.

Envelope 2 covering the rear part of the burner serves the purpose ofcovering and heat protection of electric motor l and electric lead-in21, beside esthetical reasons. Igniting member 15 and flame monitor 16,mounted on a reinforcing rib 17 of the gas nozzle, ensure the completeautomatization of the operation of the burner. Conduit 23 serves forsupplying fuel, for example natural gas, to the nozzle 20. A sealinggasket 25 is provided for preventing gas to stream into the interior ofthe burner.

A full-flame -reduced flame method is adapted for controlling low orhigh heating output; when the solenoid 11 is switched on, high heatingoutput is secured, when it is switched off, low or simmer" heat issupplied.

The burner assembly according to the invention has the following mainadvantages:

It is simpler and easier to manufacture than the conventional devices.The casing can be made of metal tubes and sheets.

A single solenoid is necessary for regulating heat output (which may becontrolled by the steam pressure of the furnace or by its temperature)as well as the gas-air proportion.

Owing to the special design of the axially displaceable'mixing cone, itis suited for controlling not only heat output and gas-air proportionbut also the turbulence and thus the length of flame. The innerresistance of the burner is small, owing to the greatly simplifiedcontrol members, so that it is possible to reduce the size of the fanand the power input. There are no rotating components except the fan,and the sources of defects are very few, as a result of the simplicityof design.

Since the flame length outside the burner is constant, this permitsuniform loading of the firing chamber and improved efficiency.

Any known type of igniting of monitoring devices may be used with theburner assembly according to the invention, with the aid of devicesincorporated into said assembly. The burner is therefore highlyadaptable to a wide range of requirements.

It will be understood that the invention is by no means confined to thedescribed embodiment. If the components are replaced by other componentsof different design but similar operation, function and effect, thescope of the invention does not change.

What I claim is:

l. A gas burner for the combustion of gaseous fuels with a heating valueover 3,000 KcaL/Nmfi, comprising a casing, a solenoid in the casing, astationary gas nozzle mounted on the casing and having a gas inlet, anda unitary assembly coaxial with and movable under the control of saidsolenoid, said unitary assembly comprising a valve member forcontrolling flow of air through the casing, a needle valve, and a coremovable by said solenoid, said needle valve cooperating with said nozzleto regulate the flow of gas at the same time that said valve memberregulates the flow of air.

2. A burner as claimed in claim 1, and screw-threaded means foradjusting said needle valve relative to said valve member thereby toadjust the flow rate of gas relative to the flow rate of air throughsaid casing.

3. A burner as claimed in claim 1, said valve member extending radiallyoutwardly from said assembly and cooperating at its outer periphery withmeans to restrict the air flow through said casing.

4. A burner as claimed in claim 1, and a fan in said casing coaxial withsaid assembly for moving air through said casing.

5. A burner as claimed in claim 4, and means dividing the casing into atleast two chambers connected by passages, said fan being disposed in onesaid chamber and said solenoid and assembly being disposed in anothersaid chamber.

6. A burner as claimed in claim 1, and a pair of coil compressionsprings acting on said assembly in opposite directions to resistmovement of said assembly in either direction.

7. A burner as claimed in claim 1, and a helical turbulenceinducingcollar on an outside conical surface of said valve member.

1. A gas burner for the combustion of gaseous fuels with a heating value over 3,000 Kcal./Nm.3, comprising a casing, a solenoid in the casing, a stationary gas nozzle mounted on the casing and having a gas inlet, and a unitary assembly coaxial with and movable under the control of said solenoid, said unitary assembly comprising a valve member for controlling flow of air through the casing, a needle valve, and a core movable by said solenoid, said needle valve cooperating with said nozzle to regulate the flow of gas at the same time that said valve member regulates the flow of air.
 2. A burner as claimed in claim 1, and screw-threaded means for adjusting said needle valve relative to said valve member thereby to adjust the flow rate of gas relative to the flow rate of air through said casing.
 3. A burner as claimed in claim 1, said valve member extending radially outwardly from said assembly and cooperating at its outer periphery with means to restrict the air flow through said casing.
 4. A burner as claimed in claim 1, and a fan in said casing coaxial with said assembly for moving air through said casing.
 5. A burner as claimed in claim 4, and means dividing the casing into at least two chambers connected by passages, said fan being disposed in one said chamber and said solenoid and assembly being disposed in another said chamber.
 6. A burner as claimed in claim 1, and a pair of coil compression springs acting on said assembly in opposite directions to resist movement of said assembly in either direction.
 7. A burner as claimed in claim 1, and a helical turbulence-inducing collar on an outside conical surface of said valve Member. 